An electric performance test, i.e., test of a circuit board (to be called “device under test” in the present invention) such as a semiconductor integrated circuit is conducted by using an electrical connecting apparatus such as a probe card provided in a tester.
There is one of such an electrical connecting apparatus in which an electrical connecting device is disposed between a circuit board and a probe board opposing each other, and which electrical connection terminals provided on the circuit board and electrical connection terminals provided on the probe board are connected each other by means of the electrical connecting device (Patent Document 1).
In such an electrical connecting apparatus, the electrical connecting device includes an insulating board having a plurality of through holes penetrating the insulating board in its thickness direction, and a pogo pin is disposed in each through hole as a connecting pin, the connection terminals of the circuit board and the connection terminals of the probe board being connected in one-to-one correspondence. The probe board has a plurality of contacts which correspond to the connecting pins in one-to-one relationship and which are pressed against the electrical connection terminals of a device under test.
The above-mentioned conventional electrical connecting apparatus conducts a test while pressing each contact provided on the probe board against the connection terminal of the device under test, by supplying the power to the device under test through the connecting pins and contacts and loading signals from the device under test to the tester through the contacts and connecting pins. When testing, the connecting pins and contacts are divided into three kinds, that is, for earth, for a positive or a negative source, and for signal and used.
Patent Document 1—Japanese Patent Appln. Public Disclosure No. 8-139142
However, since the connecting pin has a large length dimension, external noises tend to get mixed in a signal passing the connecting pin. Particularly, as an weak electric signal from a device under test passes the connecting pin for signal, it is not possible to conduct an accurate test of the device under test if a noise gets mixed in such an imperceptible electric signal.